Telephone instrument.



H. GPPE. TELEPHONE INSTRUMENT.

APPLICATION FILED Nov. 27. I9I4.

Patented Aug. 7, 1917.

` INVENTOR- WTIVESSES:

1 e. rara, or um Yoan, N. Y.

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epesses/tien of Letters raient.

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' Application led November 27, 1914-. Serial No. 874,234.

To @ZZ whom zt may concern:

Be it known that 1 f' citizen of the United States, and resident of New York,in the county of New York and` State of New York, have invented certain' new and useful Improvements in Telephone instruments, off which the following is a specification.

My invention relates to phonetic' instru' ments adapted Vfor use as telephone transmitters, microphones, or audiphone rece1v v ers, or analogous purposes.

An object of the invention" is to lprovide an instrument of this class which will 'be senv sitive and at the same vtime durable, and' Which'/iayalso be manufactured in largeK numbers with little or no variation in the v sensitiveness, accuracy, and uniformity- .ofA

' of construction object.'

the instruments.'

The invention comprises-various features contributing to this general A3 main casing, comprisinga body andA a front piece' or cap threaded thereon, forms a housing' for the microphone and the main.

diaphragm. The said diaphragm is preferably made of glass -andwsupported'by its peripheryin anl annular. recess formed in the `casingand its cap, said recess being of sui# .cient'width topreceive packing rings or gasf kets madev of paper or other suitable mate-,

rial. These packing rings hold the diaphragm with moderate elastic pressure permitting'fre'edom of vibration, and also act as a mechanicaly bufferl to prevent breakage of the Adiaphragm when the instrument is subjected to'jars ory strain. The packing also acts as a sound insulator or dea-dener to confine the mechanical vibrations to the diaphragm, eliminating sounds due to the resonance ofthe casing so,that the electrical impulses intowhich` the sound vibrations are transformed, 'represent more faithfully and accurately the voice or othersounds it is de; sired to transmit.Y O The front .piece or cap overlylng the dlaphragm is formedwith a group of perforations which are compactlyarranged oppo-Vl site the center of thefrdiaphragm to concentrate the sound waves on the central portion of the diaphragm where they are most effective, and to further 'eiect such concentration the inner surface ofthe perforatedl plate is dished or concave, which not only reduces the thickness of said plate at the ifm of N G. PAPE, af

enedp stem protruding through a openmg in the glass diaphragm but out of the transmisison of the sound waves through said openings, but also operates in a measure to focus or deflect toward the center of the diaphragm, the sound waves reflected on'the concave surface.

The microphone button comprlses a. cylin- I.

drical body or casing, the outer periphery of which is threaded to enter a threaded Iopening in the back of the main casing, a il'ange on the said periphery'forming a stop' by soldering or otherwise.' rlhe front eleopreferably of mica, the latter 'having its periphery seated inan annular recess formed by the microphone casing and a'ring threadforming the resistance varying medium be'- tween the electrodes, are held in position by a suitable soft elastic insulating material, such as Zephyr or other yarn surrounding the electrodes and' forming a packing or fill- ,ing in the space between the mica diaphragm and the' rear wall of the microphone casing.

The front or swinging electrode `may be provided with a forwardly projecting roughcentral direct contact with the diaphragm, andv connected to the diaphragm by means of a drop of cement or other suitable material which may be applied in4 aliquid state and then allowed to harden. This method of connecting the diaphragm and electrode permits the parts to be accuratelv adjusted and thense-` curely connected without any disturbance of the adjustment and without placing any strain on any diaphragm such as occurs with the usual methods of connecting swinging electrodes. i

A protector plate attached to the back of the main casing, covers and protects the Aotherwise exposed conducting portions of the microphone, said protector plate also constituting a1wire or cord o utlet for' the led on'to the casing. The carbon particles K The casing may`be provided with projections or buttons at intervals around its periphery to prevent the instrument from rolling when laid on a desk or other support. This feature is of special value when it is desired to .use the instrument on a' table and it is made in double form as shown, for example in my Patent #1,025,992.

A .further object is to provide an instru' ment that shall' be very light in weight and at the same time strong and durable. l

Other features and advantages will appear hereinafter.

The present application discloses Aan improved means for preventing the instrument from rolling when rplaced on a flat table or support, which means is shown and claimed in my zo-pending application,

Serial No'. 80,874, filed February 28,1916. L J .f

In the accompanying drawings,-Figu1"e 1 is a' sectional elevation viewA of an instru,-4 ment constructed in accordance with the principles of myf invention. Fig. 2 isa front view of the cap or front plate. Fig.`

3 is a view of the protector plate. Fig. 4-is av sectional elevat1on..-view on a somewhat larger scale, of the microphone button and the glass diaphragm attached thereto. Fig.

5 is a view of the front electrode and the surrounding diaphra Fig. 6 is a sectional elevation of t e microphone casing and the rear electrode mounted therein.

v The main casing comprises a body 1. and

a cap or front piece 2 threaded'thereon to permit vthe cap to be set up solidly against the face of the body 1. The abutting faces of the body and 'cap may' be formed with annular recees t'o provide aF groove 36 for d the receptionof the periphery of a; diaphragm 27. .The diaphragm preferably consists of a thin glam disk. A' diaphragm made of glass or vitreous material is particularly adapted for the use in a telephonie transmitter as it is unaffected by atmos# pheric moisture or moisture from the breath, and is very elastic and possesses comparatively little inertia so that itis highly sensi.. 'tive to sound vibrations. The' diaphragm is supported at its' periphery between rings or gaskets 29 of paper or other suitable packing material placed in the groove 36 fon both sides of the diaphragm. These packing rings bear on the diaphragm with a moderate elastic pressure permitting a free vibration of the diaphragm, and also serve as a mechanical buffer to protect the diaphragm from jars or strains to which the casing may be subjected by falling or other rough usage.

The front plate or cap 2 of the casing comprises a central portion 32 provided with a set of openings 33 to permit the passage of sound waves to the diaphragm. l The perforated portion 32 is surrounded by an annular boss 32a which forms within the @as ing an annular chamber or recess 34:. The

chamber 34 may be termed a compression relief chamber as it acts as a capacity chamber' to relieve the pressure of the Sound waves confined between the diaphragm and cap 2. Compression relief or dissipating vents 35 extend from the chamber 34 through the casing to relieve the pressure in said cham' ber. Strengtheningl ribs 28 are formed on the inner face of the cap 2.

The Walls of the openings 33 are flared or tapered as shown. A compact arrangement of the openings is provided for obtaining a large' area of open space opposite..

the central portion of the diaphragm to permit a comparatively .free passage of the sound waves and to concentrate the same on the central portion ofthe diaphragm where they are most effective. According to this- Y each side of the triangle and arranged inI rows parallel with the sides of the triangle. With this arrangement cap'remains imperforate so that there is no opening directly in front of the stem 17 of the swinging electrode.

The microphone button comprises a Sup* porting body or casing 5 in which; are

.Surrounding this central group 'is a second group coin' in the form ofv ,an equilateral tri# parallel the center ofthe mounted astationary or fixed carbon elec- 'i trode andan electrode 15 connected to vi`.

brate with the main diaphragm 27. The support -5 is in the form of a cylinder a'nd comprises a wall or web 38 provided with a circular opening in which the electrode 6 is mounted. The casing A5 is provided on its outer periphery with screw threads for connecting it .with the back-of the main casing 1 which is providedwith a correspondingly threaded opening. An annular A flange 41 is formed on the periphery of the casing 5, in position to bear against the back of the casing 1 and thereby form Va stopl or gage to'accuately and definitely determine the position ofthe microphone button Within the main casing. The opening in the partition 38 yis provided with a flange 42 which may extend rearwardly and provides a suit- 'able bearing for the electrode 6. Said fiange and themouter rim of the casing form an annular recess 40. By means of this construction the electrode 6 may be accurately adjusted in the direction. of its axis to bring its front face A39` to the exact position desired relative to the front electrode 15. An important advantage is thereby obtained on a metal base plate 14 hollowed out andl from which projects forwardly a stem 17 having a threaded or roughened surface,

. said stem having a reduced neck 18 at its point of connection with the base. The electrode is carried in a circular mica diaphragm 12, secured to the electrode as by means of a threaded aluminum ring or nut 16. The diaphragm 12 is peripherally supported in van annular recess formed between the casing 5 and an aluminum ring 20 threaded thereon and bearing solidly against the front face of the casing. Packing rings 13 in said recess bear against the front and rear faces of the diaphragm. The construction and arrangement forsupporting the diaphragm 12 may be substantially the same as that set forth in connection with the main diaphragm 27 and its support.

W' 'th the arrangement described )great accuracy and uniformityr in positioning and spacing the electrodes is obtained as the front face 39 of the electrode may be accurately positioned by means of a suitable gage' and then secured in such position in the manner hereinbefore set forth, leaving the opposing faces of the electrodes exactly parallel and at, a predetermined distance apart. The :resistance varying medium comprising carbon granules 31 or other suitable material is Aheld-in position by means of a resilient or'soft packing 9 which may consist of a ring of Zephyr, or other yarn or material possessing the requisite properties.

Said packing lls the annular space between the mica diaphragm 12 and a mica disk or ring 8 forming an insulating facing for the wall 38. The front electrode 15 is preferably of somewhat smaller diameter than the fixed electrode to prevent pressure of the packing material on its periphery andi thus permit a free swinging of the electro e.

The electrode 15 is xedly connected with th glass diaphragm 27 by means of a mass, compound, or cement 30. In assembling the parts, the stem 17 projects through a central opening in the diaphragm 27, but without touching the diaphragm. The connecting material 30 is preferablv an alcoholic cement, or other suitable .insulating material which may be applied in a liquid state and then allowed to harden.' By this method of connecting .theelectrode with the'main diaphragm, theaccurate adjustment of the parts is not disturbed nor any-strain placed on either diaphragm.- At the same time a solid reliable and permanent connectlon 1s obtained.- This also forms a suitable means for connecting a diaphragm made of metal or other material than glass.

The cap 2 of the main casing is provided` at intervals around its periphery with buttons 37 which break the continuity of the circular bearing? surface and thus prevent any material rollingof the instrument when supported by its periphery on a fiat surface as a desk or table. v This means of preventing rolling is also applicable to various otherforms of telephone receivers and the like.

A protector plate 3 may be secured asyby means of screws 4 to the back of the casing 1 and covers and. protects the otherwise exposed conducting parts of the microphone.

The plate 3 also constitutes a wire or cord v outlet forthe conducting cords or wires which extend 'through an opening 25 in an extension 2li-'providing a chamber 23 to -cgntain split pin cord or wire tips. Saidt1ps are received in sockets formed in terminals 21 secured in the main casing, said terminals connected by conductors 19 to the electrodes.

The protector plate 3 hasa central receedf portion 26 reducing the thickness of the plate opposite the microphone. The plate 3 being recessed tends to prevent pressure being brought to `bear near the center' of the plate when the instrument is supported on a person, and in various other conditions of use. Such central pressure would tend to distort the main casing carrying the electrode button. The recessed portion 26 also provides a suitable space for printed matteror the like which it might not be desirable toplace on the face of the instrument.

`Modifications may be resorted to without departing from the spirit or scope of the invention, and parts of the invention may be used without others.

What I claim as new and desire to secure by Letters Patent of the United States is,-

1. In a sound transforming instrument, the combination of a thin circular glass diaphragm, means surrounding the diaphragm and forming a peripheral support therefor, a microphone comprising an electrode having a stem extending between the microphone and the diaphragm, and means forming a fixed connection between said stem and diaphragm, said means engaging a small sive means comprising an element vibratable in unison with the diaphragm, said element and diaphragm being separately supported in fixed positions in the instrument, and a connecting medium by which the said ele- 'men't is secured to the diaphragm, said medium consisting of a material which may be applied in' a liquid state, preventing any tension or strain between the diaphragm and saidelement while the instrument is inactive, which material sets and forms a rigid unyielding connection between the diaphragm and said element.

3. In a telephone instrument, the combination with a diaphragm responsive to sound vibrations, said diaphragm having a central opening, of a resistance varying element, means to support said element in a fixed position in the instrument, a stem on said element having a roughened surface and extending into said opening out of direct contact with the diaphragm, and a connecting medium between said stem and diaphragm, consisting of a homogeneous ma of material which may be applied in a liquid state, leaving the diaphragm y-t'ree froml strain or tension by said stem, and which material sets and forms an unyielding connection' between the stem and diaphragm.

` `2i. A telephone instrument comprising a casing having an approximately iiat rear face wall formed with an opening therein, a microphonev comprising an electrode disk mounted in said opening and forming a closure therefor, and a protector plate overlying lsaid plate in close proximity thereto to limit the thickness of the instrument and secured to said casing and covering said microphone, said plate at one portion of its periphery projecting a short distance onlv bevond one edge of the casing and turned back to meet the casing so that said projecting portion of said plate forms a pocket to receive cord terminals without increasing the thickness of the instrument.

5. A telephone instrument comprising a ing portion of said plate forms a pocket to i receive cord terminals without increasing the thickness of the instrument, said pocket terminating in a round-lipv cord outlet.

6*.- A telephone instrument comprising a casing having a back with an opening therein, a microphone button mounted in said opening, and a thin protector plate secured to the outside of the casing in position to cover said back and spaced therefrom a slight distance only and protecting the otherwise exposed parts of the microphone,

Vand also forming a cord or wire outlet for` the conductors leading from the microphone, said plate having a central portion of reduced thickness set in from the surrounding portion of the plate.

7. A telephone instrument comprising a casing having a back with an opening therein', a microphone rigidly mounted in said opening, and a disk like protector plate secured to the outside of the casing in position to coversaid back and spaced there- I from a slight distance only and protecting the. otherwise exposed parts of the microphone, said protector plate having a peripheral extension projecting a short distance only beyond the periphery of the casing l and providing a terminal chamber for cord terminals connecting with said conductors, without increasing the thickness of the instrument, the portion of the plate overlying "the microphone being reduced in thickness and forming .a dat circulardisk set in from the surrounding ortion of the plate.

8. In a microp one, the combination of a metal casing comprising a Hat wall formed with a central opening 'and a ange surrounding said opening and forming therewith a cylindrical surface perpendicular to the plane of said wall, and a disk electrode in said opening and aiixed at its periphery to said cylindrical surface by a metal binder.

9. In a microphone, the combination of a casing having a wall provided with a smooth p cylindrical bore, a cylindrical carbon electrode fitting in said bore, whereby in assembling the parts, the electrode is adjustable in said bore in the direction of its axis, and a metal binder integrally uniting the electrode and casing.

10. In an instrument of the class described, the combination of Aa main diaphragm formed of glass and responsive to sound vibrations, an electrode, means connecting the electrode to said diaphragm to vibrate therewith, and a mica diaphragm forming a support for the electrode and vibratable therewith, lsaid connecting means comprising a stem extending from the electrode and entering an opening in said main diaphragm, and a cement applied at said opening to the A,stein vand diaphragm without producing a Ztension or strain between the diaphragme2 11..ln a telephone` instrument, the combinatlon of electrodes having opposing parallel faces spaced apart, a resistance varying medium in the space between said faces, and means for 'supporting one of said electrodes by its periphery and petting said electrode during the assembling of the parts to l he adjusted toward or from the other electrode to accurately gage the distance between said opposing faces, and means to fixedly secure the adjusted electrode in said adjusted position.

12. The combination of a microphone casing comprising an outer cylindrical shell and an internal integral web intermediate its ends, said web formed with a central circular opening, and a cylindrical flange forming a continuation of the wall of said Opening and providing a cylindrical bearing surface, said flange forming a cylinder within and spaced from said outer shell, and a cylindrical carbon electrode fitted in said-opening and having a peripheral bearing therein, the arrangement permitting adjustment of the electrode in an axial direction in assembling, and means to lixedly secure the electrode in adjusted position in the casing.

13. A telephone instrument comprising, in combination, a fixed electrode, a swinging electrode, a variable resistance medium between the electrodes, a diaphragm, and a binder uniting the diaphragm and swinging electrode, said binder consisting of a selfhardening material which may be applied as a liquid, and which when hardened rigidly unites the diaphragm and electrode.

14. In a telephone instrument, the combination of a main diaphragm formed of glass and responsive to sound vibrations, an electrode, means connecting the electrode to said diaphragm to vibrate therewith, said connecting means comprising a material which may be applied as a liquid and which is self-hardening to fixedly unite said diaphragm and electrode, and a second diaphragm forming a support for the electrode and vibratable therewith.

l5. In a telephone instrument, the combination of a diaphragm, a vibratable resistance varying element, means to support said element and diaphragm, each independently of the other and permitting each to vibrate, and means to connect said diaphragm and said element to vibrate together, said connecting means comprising a material which may be applied as a liquid and which becomes hard and firmly unites said parts.

16. The combination of an'element vibrative in response to impulses applied thereto with a frequency within the range of frequency of sound waves, a vibrative resistance varying element, means for supporting each of said elements independently of the other, and means for connecting said elements to vibrate in unison, said connecting means comprising a cement which may be applied as a liquid and then hardens and iXedly unites Said elements.

17. In a sound transforming instrument, a glass diaphragm vibratable in response to a5 sound vibrations impressed thereon, and a swinging element of a resistance medium coperatively aiixed thereto with a binder consisting of a material applied in a comparatively liquid state as a joint between the same and preventing any material stress or strain between the diaphragm and said swinging element, which binder sets or hardens after application.

18. 1n a sound transforming instrument, the combination of a thin diaphragm of vitreous material vibrative in response tov sound waves impinging thereon, electrical resistance varying means comprising a diaphragm, and means to connect the diaphragms without placing strain' thereon while they are at rest, said connecting means comprising a binder applied as a comparatively liquid mass which sets or hardens after being applied.

19. 1n a telephone instrument, the combination of a casing, sound transforming mechanism therein, and a protector plate secured to the exterior of the casing and substantially covering the back face of the cas,- ing, said protector plate comprising a flat body portion spaced a short distance only from the casing, and a surrounding peripheral portion lying against and fixed to the casing adjacent its periphery, said lbody portion being set in from the surrounding portion and thereby protected from pressure applied to said plate.

20. A sound conveyer or converter, having a disk or plate, concave on the interior and exterior, and comprising a central perforated portion, said interior concavity being provided with an annular groove which surrounds the concavity, and forms a compression chamber for sound waves enterin through the central perforations.

21. r1`he combination of a diaphragm, an inclosing casing having an annular seat for the diaphragm, said casing comprising a disk or plate in front of the diaphragm and having a perforated central portion for the passage of sound waves to the diaphragm, said plate formed on its inner surface with an. annular recess or hollow between the perforated central portion and said seat and-A serving as a capacity chamber for the sound waves. v

22. The combination of a diaphragm, an inclosing casing having an annular seat for the diaphragm, said casing comprising a disk or plate in front of the diaphragm and having a perforated central portion for the passage of sound waves to the diaphragm, the inner surface of said central portion being concave, said plate formed on its inner surface with an annular recess or hollow between the perforated central ortion and said seatcand serving as a capacity chamber for the sound waves.

523. A sound conveyer or converter, having a diskI or plate, concave on the interior and exterior, and comprising a central perforated portion, said interior concavity being provided with an annular groove which surrounds the concavity and forms a compression chamber for sound waves entering through the central perforations, said plate being provided with perforations leading from said annular groove to the outside of the plate.

l@ 24. rlfhe combination of a diaphragm, an inclosing casing having an annular seat for the diaphragm, said casing comprising a disk or plate in front of the diaphragm and having a perforated central portion for the passage of sound waves to the diaphragm, said plate formed on its inner surface with an annular recess or hollow between the perforated central portion and said seat and serving as a capacity chamber for the sound waves, said plate being provided with perforations leading from said annular recess to the outside of the plate.

25. An instrument comprising a casing, electric current carrying parts or members within the casing, said parts extending into one of the walls of the casing and having electric terminal connectors leading to the outsideof the casing, and a protector plate secured to said casing and covering the otherwise exposed electric current carryingv members and terminal connectors, said plate lying in close proximity to said wall of the casing to limit the thickness of the instrument, and extending a short distance be-l yond one edge of the casing and ,turned back to meet the casing and thereby form a pocket in the protector plate for thereception of cord terminals, said extension terminating in a round lip cord outlet.

26. In a telephone instrument, the combination with a diaphragm, of a plate having openings opposite the central portion of the diaphragm for the passage of sound waves, said openings comprising a central Igroup consisting of three openings arranged in the form of a triangle around the imperforate center of the plate, andopenings surrounding the rst group, all of the openings being substantially equal in size, each opening of the central group forming with any two of the adjacent surrounding openings a triangular group, the openings of each group being equally spaced, so that the lines joining the centers of the openings in any of said groups form an equilateral triangle, the distance between the openings in each group being substantially equal to or less than the diameter of the openings.

27. In a sound transforming instrument,

50 the combination of a diaphragm, and a protecting plate or web therefor-having openings for the transmission of sound waves,

said openings being equally spaced, of equal size and closely arranged so that the distance between adjacent openings is substantially equal to or less than the diameter of the openings, each opening forming with two adjacent openings a triangular group,the centers of the openings for each group forming the apexes of an equilateral triangle.

:28. A protecting plate for a telephone instrument consisting of a plate of a size to fitsuch instrument having an imperforate center and formed with openings for the transmission of sound waves, said openings being equally spaced, of equal size and closely arranged so that the distance between adjacent openings is substantially equalto or less than the diameter ofthe openings, each opening forming with adjacent openings a triangular group, the centers of the openings for each group forming the apexes of an equilateral triangle.

S29. ln a sound transforming instrument, the combination of a diaphragm, and a protecting plate therefor having openings for the transmission of sound waves, the walls of said openings being flared to form funnel shaped passages through the plate, said openings comprising a central group of sa three equally spaced openings surrounding the imperforate center of the plate, and openings surrounding said central group, all of the openings being of equal size, closely arranged and equally spaced, so that each opening forms with adjoining openings a triangular group or groups of equally spaced openings, the distance between the openings in each group being substantially equal to or less than the diameter of the in@ openings.

30. ln a sound transforming instrument, the combination with a diaphragm, of electrical resistance varying means comprising a vibrative element, and means to unite said element and diaphragm including a binder -which is applied in a liquid state and then allowed to harden.

3l. ln a sound transforming instrument, the combination with a microphone and a co-acting member therefor having adjoining portions, of a connecting medium consisting of a material which may be applied in a liquid state for ixedly uniting the adjoining portions of said microphone and 11s saidvco-acting member, so that the microphone and co-acting member will vibrate in unison, said medium consisting of a material which may be applied in a comparatively liquid state, preventing any strain between the microphone and said co-acting member while said parts are at rest.

32. In a sound transforming instrument, the combination with a microphone having a swinging electrode, and a diaphragm, means extending between said electrode and diaphragm by which they are united to vibrate together, said uniting means comprising a material which may be applied as a liquid, but which after it is applied is caused to harden and thereby complete turned back toward the casing so as to form the connection. a pocket for cord terminals, said extension 33. In an instrument of the class described, terminating a short distance beyond the cas- 15 a casing comprising working elements or in in a round lip cord outlet. 5 conducting parts and a peripheral wall carigned at New York, in the county of rying exposed connecting terminals, of a New York and State of New York this 23rd protector plate secured to said casing and day of November, A. D. 1914.

covering the said exposed working elements or conductin parts and the said connecting HERMAN G PAPE' 10 terminals, sa1d plate having an integral ex- Witnesses:

tension at one part of its periphery project- IDA B. PAPE,

ing beyond the edge of the casing andv IDA D. PAPE. 

